JP2020002874A - Internal combustion engine control device - Google Patents

Abstract

To provide an internal combustion engine control device capable of curbing a reduction in accuracy of controlling an air-fuel ratio.SOLUTION: A CPU 52: calculates a required injection amount on the basis of an amount of air filled in a combustion chamber 24 when an operation speed of an intake side valve timing regulation device 44 is high; and injects a portion of the required injection amount in advance as a first asynchronous injection amount. Then, the CPU 52: updates the required injection amount on the basis of the newly acquired amount of air; calculates a synchronous injection amount, according to an update result, which is an amount of intake synchronous injection in which fuel is injected in synchronization with an opening period of an intake valve 18; substitutes a value obtained by subtracting the first asynchronous injection amount and the synchronous injection amount from the required injection amount into a second asynchronous injection amount; and injects the synchronous injection amount of fuel after injecting the second asynchronous injection amount of fuel.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a control device for an internal combustion engine that is applied to an internal combustion engine that includes a port injection valve that injects fuel into an intake passage and an actuator that controls the flow of a fluid into a combustion chamber.

  For example, Patent Document 1 described below discloses a control device that injects a required amount of fuel in three divided injections in one combustion cycle determined according to the intake air amount in a high load region (paragraph “0016”). And FIG. 6 (B)).

JP 2015-59456 A

  When the required amount of fuel is injected in a plurality of times in one combustion cycle as described above, the amount of fuel required in one combustion cycle may be calculated prior to the first injection. In this case, when the actuator that adjusts the flow of the fluid into the combustion chamber is operating when calculating the injection amount, the amount of air charged into the combustion chamber deviates from the assumption, and the air-fuel ratio is controlled to a target value. May not be possible.

Hereinafter, means for solving the above-mentioned problems and the effects thereof will be described.
1. A control device applied to an internal combustion engine including a port injection valve for injecting fuel into an intake passage, and an actuator for adjusting the flow of fluid into a combustion chamber, wherein a predicted value of an amount of air flowing into the combustion chamber is provided. A required injection amount calculation process for calculating a required injection amount, which is a required fuel amount in one combustion cycle, and a synchronous injection amount, which is an injection amount of intake synchronous injection for injecting fuel in synchronization with an opening period of the intake valve. The required injection amount is divided into an injection amount and an asynchronous injection amount that is an injection amount of an intake asynchronous injection that injects fuel at a timing that is more advanced than the intake synchronous injection, and the port injection valve is operated. A multi-injection process in which the intake asynchronous injection and the intake synchronous injection are performed in this order; and a selection for selecting whether to execute the intake asynchronous injection separately in two or only once prior to the intake synchronous injection. When the asynchronous intake injection is divided into two and executed, the required injection amount is updated prior to performing the intake asynchronous injection for the second time, and the asynchronous injection amount and An update process for updating the synchronous injection amount is executed, and the selecting process selects to execute the intake asynchronous injection in two separate steps when a change rate of the control amount by the reference actuator is equal to or higher than a predetermined speed. The reference actuator is a control device for an internal combustion engine, wherein the change speed of the control amount is referred to in the selection process of the actuator.

  When all the fuel of the required injection amount is injected by intake asynchronous injection when the temperature of the intake system of the internal combustion engine is low, the number (PN) of particulate matter (PM) in the exhaust may increase depending on the load. . It is presumed that this is because the amount of fuel adhering to the intake system increases and a part of the adhering fuel flows into the combustion chamber as droplets due to shearing of the fuel, thereby generating PM. Therefore, in the above configuration, the asynchronous injection amount is reduced by injecting a part of the required injection amount by synchronous injection, and the fuel amount attached to the intake system is reduced. This can prevent the fuel from flowing into the combustion chamber as droplets due to the shearing of the attached fuel.

  However, when the required injection amount is calculated by the required injection amount calculation process prior to the intake asynchronous injection, when the change speed of the control amount by the reference actuator is equal to or higher than a predetermined speed, the actual air amount is assumed when calculating the required injection amount. Therefore, the controllability of the air-fuel ratio may be reduced. Therefore, in the above configuration, the intake asynchronous injection is divided into two times, and the required injection amount is updated prior to the second injection. Thereby, the sum of the asynchronous first injection amount, the asynchronous second injection amount, and the synchronous injection amount can be set as the updated required injection amount. For this reason, it is possible to suppress a decrease in the control accuracy of the air-fuel ratio.

  2. The reference actuator includes a valve characteristic variable device that changes at least one of two timings, that is, a start timing of opening an intake valve and a start timing of closing a exhaust valve, and the selection process includes a control by the reference actuator. The internal combustion engine according to claim 1, further comprising a process of selecting execution of the intake asynchronous injection in two separate steps when the rate of change of the control amount by the valve characteristic variable device is equal to or higher than the predetermined rate. Control device.

  When the rate of change of the control amount by the valve characteristic variable device that changes the opening timing of the intake valve is equal to or higher than a predetermined speed, the amount of air flowing into the combustion chamber may change significantly. Further, when the rate of change of the control amount by the valve characteristic variable device that changes the closing timing of the exhaust valve is equal to or higher than a predetermined speed, the length of the overlap period between the opening period of the intake valve and the opening period of the exhaust valve. Is greatly changed, the amount of air flowing into the combustion chamber may be greatly changed. Therefore, in the above configuration, when the change rate of the control amount by the valve characteristic variable device is equal to or higher than a predetermined speed, the asynchronous intake injection is divided into two times, and the required injection amount is updated prior to the second intake asynchronous injection. Accordingly, the required injection amount calculated based on more accurate information on the amount of air flowing into the combustion chamber can be used.

  3. The internal combustion engine includes an EGR passage that communicates the intake passage with an exhaust passage of the internal combustion engine. The reference actuator includes an EGR valve that adjusts a cross-sectional area of the flow passage in the EGR passage. The method according to the above-described item 1, further comprising the step of selecting to execute the intake asynchronous injection in two separate steps when the rate of change of the degree of opening of the EGR valve is equal to or higher than the predetermined rate as the rate of change of the control amount by the reference actuator. It is a control device of the internal combustion engine described.

  When the rate of change of the opening degree of the EGR valve is equal to or higher than a predetermined speed, the amount of air flowing into the combustion chamber may greatly change due to the change of the opening degree. Therefore, in the above configuration, when the changing speed of the opening degree of the EGR valve is equal to or higher than the predetermined speed, the intake asynchronous injection is divided into two times, and the required injection amount is updated prior to the second intake asynchronous injection. The required injection amount calculated based on more accurate information on the amount of air flowing into the combustion chamber can be used.

  4. The intake passage is provided with a throttle valve, an opening target value setting process for setting an opening target value of the throttle valve according to an accelerator operation amount, and a delay process for delaying the opening target value. A throttle control process for controlling the opening degree of the throttle valve to the target opening degree subjected to the delay processing; and the required injection amount calculation processing based on the target opening degree before the delay processing is performed. 4. The control device for an internal combustion engine according to the above 2 or 3, which executes a prediction process of calculating the predicted value.

  In the above configuration, the opening degree of the throttle valve is controlled to the target opening degree subjected to the delay processing, and the air amount is predicted based on the target opening degree before the delay processing is performed, so that the prediction accuracy can be improved. . For this reason, the air amount in the future about the time interval having the length of the delay time due to the delay processing with respect to the closing timing of the intake valve is calculated with high accuracy unless the change rate of the control amount of the other actuator is large. can do.

  5. The reference actuator does not include the throttle valve, and the selection process selects the asynchronous intake injection divided into two when the rotation speed of the crankshaft of the internal combustion engine is lower than a specified speed. When the rotation speed is equal to or higher than the specified speed and lower than a predetermined speed that is higher than the specified speed, and when the change speed of the control amount by the reference actuator is equal to or higher than the predetermined speed, the intake asynchronous operation is performed. The method according to claim 4, further comprising: a process of selecting to execute the injection divided into two times; and a process of selecting to perform the intake asynchronous injection once when the rotation speed is equal to or higher than the predetermined speed. It is a control device for an internal combustion engine.

  Even if the prediction process is executed, if the required injection amount is calculated at a timing on the advance side by a time interval longer than the delay time due to the delay process with respect to the closing timing of the intake valve, the accuracy of the prediction process becomes higher. descend. Therefore, in the above configuration, when the rotational speed of the crankshaft is lower than the specified speed, the asynchronous intake injection is executed in two parts, and the required injection amount is updated prior to the second intake asynchronous injection. In addition, it is possible to suppress a decrease in the calculation accuracy of the injection amount. If the rotation speed is equal to or higher than the specified speed but lower than the predetermined speed, the asynchronous intake injection is executed in two parts when the speed of change of the control amount by the reference actuator is large, and the second intake asynchronous injection is performed. The required injection amount is updated prior to executing the injection. Thus, even when the speed of change of the control amount by the reference actuator is high, it is possible to suppress a decrease in the calculation accuracy of the required injection amount.

FIG. 1 is a diagram showing a control device and an internal combustion engine according to one embodiment. FIG. 2 is an exemplary block diagram illustrating processing executed by the control device according to the embodiment. (A) And (b) is a figure showing the ejection pattern concerning the embodiment. 3 is a flowchart showing a procedure of an injection valve operation process according to the embodiment. 3 is a flowchart showing a procedure of an injection valve operation process according to the embodiment.

Hereinafter, an embodiment of a control device for an internal combustion engine will be described with reference to the drawings.
A throttle valve 14 is provided in the intake passage 12 of the internal combustion engine 10 shown in FIG. 1, and a port injection valve 16 is provided downstream of the throttle valve 14. The air sucked into the intake passage 12 and the fuel injected from the port injection valve 16 flow into the combustion chamber 24 defined by the cylinder 20 and the piston 22 with the opening of the intake valve 18. In the combustion chamber 24, a mixture of fuel and air is burned by spark discharge of an ignition device 26, and combustion energy generated at that time is converted into rotational energy of a crankshaft 28 via a piston 22. . The air-fuel mixture supplied to the combustion is discharged to the exhaust passage 32 as exhaust gas when the exhaust valve 30 is opened. A catalyst 34 is provided in the exhaust passage 32.

  The downstream side of the throttle valve 14 in the intake passage 12 is connected to the exhaust passage 32 via an EGR passage 36. The EGR passage 36 is provided with an EGR valve 37 for adjusting the cross-sectional area of the passage.

  The rotational power of the crankshaft 28 is transmitted to an intake camshaft 40 and an exhaust camshaft 42 via a timing chain 38. In this embodiment, the power of the timing chain 38 is transmitted to the intake-side camshaft 40 via the intake-side valve timing adjusting device 44. The intake valve timing adjustment device 44 is an actuator that adjusts the valve opening timing of the intake valve 18 by adjusting the rotational phase difference between the crankshaft 28 and the intake camshaft 40. Further, the power of the timing chain 38 is transmitted to the exhaust-side camshaft 42 via an exhaust-side valve timing adjusting device 46. The exhaust valve timing adjustment device 46 is an actuator that adjusts the valve opening timing of the exhaust valve 30 by adjusting the rotational phase difference between the crankshaft 28 and the exhaust camshaft 42.

  The control device 50 controls the internal combustion engine 10 to control the control amounts (torque, exhaust component ratio, etc.) of the internal combustion engine 10, the throttle valve 14, the port injection valve 16, the ignition device 26, the EGR valve 37, the intake The operating parts of the internal combustion engine 10, such as the side valve timing adjustment device 44 and the exhaust side valve timing adjustment device 46, are operated. At this time, the control device 50 is provided in the output signal Scr of the crank angle sensor 60, the intake air amount Ga detected by the air flow meter 62, the opening degree TA of the throttle valve 14 detected by the throttle sensor 64, and the exhaust passage 32. The air-fuel ratio Af detected by the measured air-fuel ratio sensor 66 is referred to. Further, the control device 50 refers to the output signal Scai of the intake-side cam angle sensor 70 and the output signal Scae of the exhaust-side cam angle sensor 72. The control device 50 also controls the temperature of the cooling water (water temperature THW) of the internal combustion engine 10 detected by the water temperature sensor 74, the atmospheric pressure Pa detected by the atmospheric pressure sensor 76, and the operation of the accelerator pedal detected by the accelerator sensor 78. The amount (accelerator operation amount ACCP) is referred to.

  The control device 50 includes a CPU 52, a ROM 54, and a power supply circuit 56 that supplies power to each part in the control device 50. The CPU 52 executes a program stored in the ROM 54 to control the control amount. I do.

FIG. 2 shows a part of the processing executed by the control device 50. The process shown in FIG. 2 is realized by the CPU 52 executing a program stored in the ROM 54.
The intake phase difference calculation processing M10 is based on the output signal Scr of the crank angle sensor 60 and the output signal Scai of the intake cam angle sensor 70, and calculates the phase difference between the rotation angle of the crankshaft 28 and the rotation angle of the intake camshaft 40. This is a process for calculating a certain intake phase difference DIN. The target intake phase difference calculation process M12 is a process for variably setting the target intake phase difference DIN * based on the operating point of the internal combustion engine 10. In this embodiment, the operating point is defined by the rotation speed NE and the charging efficiency η. Here, the CPU 52 calculates the rotation speed NE based on the output signal Scr of the crank angle sensor 60, and calculates the charging efficiency η based on the rotation speed NE and the intake air amount Ga. The charging efficiency η is a parameter that determines the amount of air charged into the combustion chamber 24.

  The intake phase difference control process M14 is a process of outputting an operation signal MS4 to operate the intake side valve timing adjustment device 44 in order to perform feedback control of the intake phase difference DIN, which is a control amount, to the target intake phase difference DIN *. .

  The exhaust phase difference calculation processing M16 is based on the output signal Scr of the crank angle sensor 60 and the output signal Scae of the exhaust cam angle sensor 72, and calculates the phase difference between the rotation angle of the crank shaft 28 and the rotation angle of the exhaust cam shaft 42. This is a process for calculating a certain exhaust phase difference DEX. The target exhaust phase difference calculation process M18 is a process for variably setting the target exhaust phase difference DEX * based on the operating point of the internal combustion engine 10 and the target intake phase difference DIN *. More specifically, the target exhaust phase difference calculation process M18 is based on the operating point of the internal combustion engine 10, and the overlap amount is the length of the overlap period in which the opening period of the intake valve 18 and the opening period of the exhaust valve 30 overlap. (Crank angle interval) is calculated, and the target exhaust phase difference DEX * is calculated based on the overlap amount and the target intake phase difference DIN *.

  The exhaust phase difference control process M20 is a process of outputting an operation signal MS5 to operate the exhaust-side valve timing adjusting device 46 in order to feedback-control the exhaust phase difference DEX, which is a control amount, to the target exhaust phase difference DEX *. .

  The EGR opening degree calculation processing M22 is a processing for calculating an EGR target value θ *, which is a target value of the opening degree of the EGR valve 37, based on the operating point of the internal combustion engine 10. The EGR control process M24 is a process of outputting an operation signal MS6 to the EGR valve 37 to operate the EGR valve 37 to control the opening degree of the EGR valve 37, which is a control amount, to the EGR target value θ *. In the present embodiment, the opening degree of the EGR valve 37 as a control amount is controlled in an open loop to the EGR target value θ *.

  The opening target value setting process M30 is a process of setting a target opening value of the throttle valve 14 (target opening TA *) based on the accelerator operation amount ACCP. Specifically, the opening target value setting process M30 is a process of setting the target opening TA * to a larger value when the accelerator operation amount ACCP is larger than when the accelerator operation amount ACCP is smaller.

  The delay process M32 is a process for calculating a delay opening degree TAr obtained by delaying the target opening degree TA * by a predetermined delay time. The throttle control process M34 is a process of outputting an operation signal MS1 to operate the throttle valve 14 in order to feedback-control the opening degree TA detected by the throttle sensor 64 to the delay opening degree TAr.

  When assuming that the actual aperture TA is controlled to the target aperture TA *, the low-pass filter M36 takes into account that the actual aperture TA is delayed with respect to a change in the target aperture TA *, and accordingly, the target aperture TA * Is a process of outputting the first-order lag processing value of the above as the predicted opening degree TAe.

  The throttle model M38 is a process for calculating a throttle flow rate mt, which is an amount of air passing through the throttle valve 14, based on the intake pressure Pm1 calculated by a process described later, the predicted opening degree TAe, and the atmospheric pressure Pa. Specifically, the throttle model M38 is a process of calculating the throttle flow rate mt to a larger value when the atmospheric pressure Pa is high than when it is low. The throttle model M38 is a process for calculating the throttle flow rate mt to a smaller value when the intake pressure Pm1 is high than when it is low. The throttle model M38 is a process of calculating the throttle flow rate mt to a larger value when the predicted opening degree TAe is larger than when the predicted opening degree TAe is smaller. More specifically, the throttle model M38 calculates the throttle flow rate mt based on a model formula that relates the predicted opening degree TAe, the atmospheric pressure Pa, and the intake pressure Pm1, which are input parameters, and the throttle flow rate mt, which is an output parameter. It is. The model formula is not limited to a formula that directly connects the input parameters and the output parameters. For example, a coefficient of the formula may be variably set according to the input parameter.

  The intake manifold model M40 is a process for calculating the intake pressure Pm1 based on the valve-closing inflow air amount Mc1 calculated by a process described later, the throttle flow rate mt, and the EGR target value θ *. The valve-closing inflow air amount Mc1 is a value excluding the amount of air that has flowed back into the intake passage 12 by the time the intake valve 18 closes, out of the amount of air that flows into the combustion chamber 24 in one combustion cycle. Specifically, the intake manifold model M40 calculates the intake pressure Pm1 such that the rate of increase of the intake pressure Pm1 is larger when the value obtained by subtracting the valve closing inflow air amount Mc1 from the throttle flow rate mt is larger than when the value is smaller. This is the process of

  The intake valve model M42 is a process for calculating the valve-closing inflow air amount Mc1 based on the intake pressure Pm1, the intake phase difference DIN, and the rotational speed NE. The intake valve model M42 is a process of calculating the valve-closing inflow air amount Mc1 to be larger when the intake pressure Pm1 is higher than when it is lower. In addition, the intake valve model M42 has a smaller valve closing-time inflow air amount Mc1 as the intake phase difference DIN is more retarded when the valve closing timing of the intake valve 18 is more retarded than BDC. This is the process of calculating.

  The steady value correction process M44 is a process of calculating a correction amount ΔPm for correcting the intake pressure Pm1 to a value corresponding to the intake air amount Ga in a steady state based on the intake air amount Ga and the opening degree TA. is there. The correction process M46 is a process of calculating the intake pressure Pm by subtracting the correction amount ΔPm from the intake pressure Pm1. The intake pressure Pm matches the intake pressure grasped from the intake air amount Ga in the steady state, and has a value that emphasizes the responsiveness of the intake pressure Pm1 in the transient state.

  The steady-state value correction process M44 may be, for example, a process of executing the following two processes as an intake pressure estimation process and calculating the difference between them as a correction amount ΔPm. That is, the first estimation process is a process in which the same model as the throttle model M38, the intake manifold model M40, and the intake valve model M42 is used, but the opening degree TA is input instead of the predicted opening degree TAe. On the other hand, the second estimation process is a process using the same model as the intake manifold model M40 and the intake valve model M42, and using the intake air amount Ga instead of the throttle flow rate mt. Here, in the steady state, the intake pressure estimated by the first estimation process is an intake pressure based on the amount corresponding to the throttle flow rate mt. Therefore, the correction amount ΔPm is the intake air amount of the throttle flow rate mt in the steady state. This is a value that compensates for an error with respect to Ga. On the other hand, in the transient state, the responsiveness of the intake pressure estimated by the first estimation process approximates the responsiveness of the intake pressure estimated by the second estimation process. The value is such that the change in the intake pressure Pm1 can be made to be obvious in the intake pressure Pm.

  The intake valve model M48 is a process in which the intake pressure Pm, the intake phase difference DIN, and the rotational speed NE are used as input parameters, and the valve closing inflow air amount Mc as an output parameter is calculated based on the input parameters. Although the intake valve model M48 has different input parameters from the intake valve model M42, the process itself of calculating the output parameters based on the input parameters is a portion that performs the same process.

  The valve-closing inflow air amount Mc is a predicted value of the amount of air sucked into the combustion chamber 24, and more specifically, is a predicted value reflecting the state of the throttle valve 14 in the future by the delay time. This is because while the throttle valve 14 is controlled to the delay opening degree TAr, the valve closing inflow air amount Mc is a value when the opening degree of the throttle valve 14 is controlled to the target opening degree TA *. is there.

  The injection valve operation process M50 is a process of operating the port injection valve 16 by taking in the inflow air amount Mc at closing time, the intake phase difference DIN, the rotation speed NE, the intake pressure Pm, the water temperature THW, and the air-fuel ratio Af.

The injection valve operation process M50 basically has two processes, a process illustrated in FIG. 3A and a process illustrated in FIG. 3B.
FIG. 3A shows two types of intake synchronous injection, that is, intake synchronous injection in which fuel is injected in synchronization with the opening period of the intake valve 18 and intake asynchronous injection in which fuel is injected at a more advanced timing than intake synchronous injection. This is a multi-injection process for executing fuel injection. More specifically, in the intake synchronous injection, a period during which the fuel injected from the port injection valve 16 reaches the position before the opening of the intake valve 18 (the downstream end of the intake port, in other words, the entrance to the combustion chamber 24) is provided. The fuel is injected so as to fall within the opening period of the intake valve 18. Here, the start point of the “arrival period” is the timing at which the fuel injected at the earliest timing among the fuels injected from the port injection valve 16 reaches the position before the valve is opened, and the end point is the port injection timing. This is the timing at which the fuel injected at the latest timing among the fuels injected from the valve 16 reaches the position before the valve is opened. On the other hand, the intake asynchronous injection is to inject fuel so that the fuel injected from the port injection valve 16 reaches the intake valve 18 before the intake valve 18 opens. In other words, the intake asynchronous injection is an injection in which the fuel injected from the port injection valve 16 stays in the intake passage 12 until the intake valve 18 opens, and flows into the combustion chamber 24 after opening. is there. Note that, in the present embodiment, the intake asynchronous injection is such that the fuel injected from the port injection valve 16 reaches the position before the intake valve 18 opens before the intake valve 18 closes. Shall be.

FIG. 3B shows a single injection process for executing only the intake asynchronous injection.
In the present embodiment, the multi-injection process is executed with the aim of reducing the number (PN) of particulate matter (PM) in the exhaust gas. That is, when the temperature of the intake system of the internal combustion engine 10 such as the intake passage 12 and the intake valve 18 is low to some extent, the PN tends to increase when the single injection process is executed in a region where the charging efficiency η is relatively high. This is because when the charging efficiency η is large, the required injection amount Qd, which is the amount of fuel required to be injected per combustion cycle, is larger than when it is small, and as a result, the amount of fuel adhering to the intake system It is considered that this is caused by the increase in More specifically, it is presumed that when the amount of fuel attached to the intake system increases to a certain extent, a part of the attached fuel flows into the combustion chamber 24 as droplets due to the shearing of the attached fuel. Therefore, in the present embodiment, by injecting a part of the required injection amount Qd by the intake synchronous injection, even if the required injection amount Qd is large, the amount of fuel adhering to the intake system is divided by the large required injection amount Qd. And PN is reduced.

  However, when the rotational speed NE is low, the time from the timing of calculating the injection amount based on the valve closing inflow air amount Mc prior to the intake asynchronous injection to the time of closing the intake valve 18 becomes longer than the delay time. As a result, the valve-closing inflow air amount Mc that can be used for calculating the required injection amount Qd becomes a past timing with respect to the end of the suction stroke. In this case, an error may occur in the valve-closing inflow air amount Mc used for calculating the required injection amount Qd with respect to the actual air amount charged into the combustion chamber 24 when the intake valve 18 is closed. This may cause the air-fuel ratio to deviate from the target value.

Therefore, in the present embodiment, the following processing is executed to suppress the deviation of the air-fuel ratio.
FIG. 4 shows a procedure of the injection valve operation process M50. The process shown in FIG. 4 is realized by CPU 52 repeatedly executing a program stored in ROM 54 at, for example, a predetermined cycle. In the following, the step number of each process is represented by a number with “S” added at the beginning.

  In the series of processes shown in FIG. 4, the CPU 52 first calculates the required injection amount Qd based on the above-mentioned valve-closing inflow air amount Mc (S10). Specifically, the CPU 52 calculates the charging efficiency η from the ratio of the valve-closing inflow air amount Mc to the maximum value of the air amount charged into the combustion chamber 24, and adds one unit of the charging efficiency η to the charging efficiency η. Is multiplied by an injection amount necessary for setting the air-fuel ratio to the target air-fuel ratio to calculate a base injection amount Qb. Then, the CPU 52 corrects the base injection amount based on the feedback correction coefficient KAF, which is an operation amount for performing feedback control of the air-fuel ratio Af to the target value, and the low-temperature increase coefficient Kw corresponding to the water temperature THW, thereby obtaining the required injection amount Qd. Is calculated. The CPU 52 sets the low temperature increase coefficient Kw to a larger value when the water temperature THW is low than when it is high, and increases the increase correction ratio of the base injection amount Qb.

  Next, the CPU 52 determines whether there is a request for the multi-injection process (S12). Here, when the logical product of the following conditions (A), (A), and (C) is true, the CPU 52 determines that there is a request to execute the multi-injection process.

  Condition (A): A condition that the charging efficiency η is equal to or higher than a predetermined value. This condition is that if the single injection process is performed, the amount of fuel adhering to the intake passage 12 becomes excessively large, and the PN may become significant.

  Condition (a): A condition that the rotational speed NE is equal to or lower than a predetermined speed NEth. This condition is a condition that a time interval between the end timing of the intake asynchronous injection and the start timing of the intake synchronous injection can be secured to a predetermined time or more determined by the structure of the port injection valve 16. In addition, this condition is a condition for suppressing an excessive heat generation due to an increase in the calculation load of the control device 50 because the calculation load of the multi-injection process is greater than that of the single injection process.

  Condition (C): A condition that the water temperature THW is equal to or lower than a specified temperature Tth (for example, 60 ° C.). This condition is a condition that the amount of fuel adhering to the intake passage 12 becomes large, and PN may become remarkable.

  When determining that there is a request for the multi-injection process (S12: YES), the CPU 52 determines whether or not there is a request to split the intake asynchronous injection into two injections (S14). This will be described in detail later. If the CPU 52 determines that there is a request to inject the fuel into two injections (S14: YES), the CPU 52 multiplies the required injection amount Qd by the first injection ratio K1 on the advanced side of the intake asynchronous injection. It is substituted into the injection amount of the asynchronous first injection (asynchronous first injection amount Qns1) (S16). The first injection ratio K1 is a value larger than “0” and smaller than “1”, and determines the ratio of the asynchronous first injection amount Q1 in the fuel of the required injection amount Qd.

  When the process of S16 is completed, the CPU 52 waits until the injection start timing of the asynchronous first injection (the asynchronous first injection start timing Ins1) (S18: NO), and when the asynchronous first injection start timing Ins1 is reached (S18). : YES), the operation signal MS2 is output to the port injection valve 16, and the fuel of the asynchronous first injection amount Qns1 is injected from the port injection valve 16 (S20). The CPU 52 sets the asynchronous first injection start timing Ins1 to a more advanced side when the water temperature THW is low than when it is high. This is because when the water temperature THW is low, the required injection amount Qd has a larger value than when the water temperature THW is high, so that the rotation angle interval of the crankshaft 28 required to execute three fuel injections is widened. .

  Thereafter, the CPU 52 updates the required injection amount Qd based on the newly calculated valve closing inflow air amount Mc after the processing of S10 (S22). This process is a process for updating the required injection amount to a more accurate injection amount. Then, the CPU 52 calculates the synchronous injection amount Qs, which is the injection amount of the intake synchronous injection, based on the charging efficiency η, the rotation speed NE, the water temperature THW, and the intake phase difference DIN referred to in the processing of S22 (S24). . More specifically, the CPU 52 sets the synchronous injection amount Qs by the CPU 52 in a state where map data having the charging efficiency η, the rotational speed NE, the water temperature THW, and the intake phase difference DIN as input variables and the synchronous injection amount Qs as output variables is stored in the ROM 54 in advance. Perform a map operation.

  Note that the map data is a set of discrete values of the input variables and output variable values corresponding to the input variable values. In addition, for example, when the value of the input variable matches any of the values of the input variables of the map data, the map operation is performed using the value of the output variable of the corresponding map data as the calculation result. What is necessary is just to make the value obtained by interpolation of the value of several output variables into a calculation result.

  Next, the CPU 52 subtracts the asynchronous first injection amount Qns1 and the synchronous injection amount Qs from the requested injection amount Qd updated by the process of S22, and calculates the asynchronous second injection amount, which is the injection amount of the second intake asynchronous injection. The value is substituted into the injection amount Qns2 (S26). Thus, the sum of the asynchronous first injection amount Qns1, the asynchronous second injection amount Qns2, and the synchronous injection amount Qs becomes the required injection amount Qd updated in the process of S22. That is, the total injection amount injected in one combustion cycle is determined based on the required injection amount Qd updated by the process of S22.

  Then, the CPU 52 waits until the asynchronous second injection start timing Ins2, which is the injection start timing of the second intake asynchronous injection, (S28: NO), and when the asynchronous second injection start timing Ins2 is reached (S28: YES), The operation signal MS2 is output to the port injection valve 16 to inject the asynchronous second injection amount Qns2 of fuel from the port injection valve 16 (S30). Next, the CPU 52 waits until the synchronous injection start timing Is, which is the injection start timing of the intake synchronous injection, (S32: NO). When the synchronous injection start timing Is comes (S32: YES), the CPU 52 operates the port injection valve 16. The signal MS2 is output to inject the synchronous injection amount Qs of fuel from the port injection valve 16 (S34).

  Incidentally, the synchronous injection start timing Is is calculated based on the rotational speed NE, the charging efficiency η, the water temperature THW, and the intake phase difference DIN. Here, the CPU 52 sets the synchronous injection start timing Is to the advanced side when the water temperature THW is lower than when it is high. When the valve opening timing of the intake valve 18 is on the advance side, and the overlap period between the valve opening period of the intake valve 18 and the valve opening period of the exhaust valve 30 becomes longer, the CPU 52 determines that the synchronous injection start timing Is Is the retard side. The asynchronous second injection start timing Ins2 is set such that the time interval between the synchronous injection start timing Is and the end timing of the second intake asynchronous injection becomes equal to or longer than the predetermined time.

  On the other hand, when the CPU 52 makes a negative determination in the process of S14, the CPU 52 executes a multiple injection process in which the intake asynchronous injection is performed once (S36). Here, in the multiple injection processing in which the intake asynchronous injection is performed once, the asynchronous injection amount Qns may be set to “Qd−Qs”. The asynchronous injection start timing is set by the same processing as the asynchronous second injection start timing Ins2. Incidentally, the asynchronous injection start timing may be on a more retarded side than the asynchronous first injection start timing Ins1.

  When the CPU 52 makes a negative determination in the process of S12, it executes a single injection process (S38). The injection start timing of the single injection process may be set according to, for example, the rotational speed NE and the charging efficiency η.

When the processing of S34 to S38 is completed, the CPU 52 ends the series of processing illustrated in FIG. 4 once.
FIG. 5 shows a procedure for determining whether there is a split request for intake asynchronous injection. The process shown in FIG. 5 is realized by CPU 52 repeatedly executing a program stored in ROM 54 at, for example, a predetermined cycle.

  In the series of processes shown in FIG. 5, the CPU 52 first determines whether or not the asynchronous first injection start timing Ins1 determined according to the water temperature THW is equal to or more advanced than the retard limit Is1th. (S40). Here, the retard limit Is1th is set to the most retarded timing at which a predetermined time can be secured between three fuel injections when the asynchronous intake injection is divided. When determining that the rotation speed NE is equal to or less than the retard limit Is1th (S40: YES), the CPU 52 determines whether the rotation speed NE is lower than the specified speed NEL (S42). The specified speed NEL is determined by the fact that the timing at which the actual charging efficiency η is determined is delayed with respect to the timing predicted as the valve closing inflow air amount Mc referred to in the process of S10, and the valve closing inflow air amount. The accuracy of the required injection amount Qd calculated based on Mc is set to about the lower limit value of the speed that does not fall outside the allowable range. When the CPU 52 determines that the air-fuel ratio is lower than the specified speed NEL, the multi-injection process in which the intake asynchronous injection is performed once based on the required injection amount Qd calculated in the process of S10, the controllability of the air-fuel ratio is reduced. It is assumed that there is a request to divide the intake asynchronous injection (S44).

  On the other hand, when determining that the rotation speed is equal to or higher than the specified speed NEL (S42: NO), the CPU 52 determines whether the rotation speed NE is lower than a predetermined speed NEH that is higher than the specified speed NEL (S46). Here, when the change speed of the intake phase difference DIN, the exhaust phase difference DEX, and the EGR target value θ * is large, the predetermined speed NEH is the valve-closing inflow air amount Mc with respect to the air amount actually charged into the combustion chamber 24. Is set to the lower limit value of the speed at which the deviation amount can exceed the allowable range. That is, when the rotational speed NE is equal to or higher than the specified speed NEL, the changing speed of the intake phase difference DIN, the exhaust phase difference DEX, and the EGR target value θ * is small even if the opening degree TA of the throttle valve 14 changes. Then, a highly accurate predicted value of the actual air amount can be referred to as the valve-closing inflow air amount Mc in the process of S10. However, in the calculation process of the valve closing inflow air amount Mc shown in FIG. 2, it is assumed that the intake phase difference DIN, the exhaust phase difference DEX, and the EGR target value θ * are steady values. The prediction processing such as the opening degree TA is not performed. Therefore, when the change speed of the intake phase difference DIN, the exhaust phase difference DEX, and the EGR target value θ * is large, the error of the valve-closing inflow air amount Mc may become significant. In particular, when the rotational speed NE is low, the time from the execution of the process of S10 to the actual charging efficiency η is determined by the closing of the intake valve 18 than when the rotational speed NE is high, so that the intake phase difference DIN And the exhaust phase difference DEX and the EGR target value θ * change, the accuracy of the valve closing inflow air amount Mc tends to be remarkably reduced.

  When determining that the speed is lower than the predetermined speed NEH (S46: YES), the CPU 52 determines whether the logical sum of the following three conditions is true (S48). That is, the condition (D) that the change amount ΔDIN of the intake phase difference DIN per unit time is equal to or more than the predetermined speed ΔDINth, and the condition that the change amount ΔDEX of the exhaust phase difference DEX per unit time is equal to or more than the predetermined speed ΔDEXth. There are three conditions: condition (e) and condition (f) that the amount of change Δθ * of the EGR target value θ * per unit time is equal to or greater than a predetermined speed Δθth. This process is a process for determining whether or not the changing speed of the intake phase difference DIN, the exhaust phase difference DEX, and the EGR target value θ * is such that the error in the valve-closing inflow air amount Mc exceeds an allowable range. .

  When determining that the logical sum is true (S48: YES), the CPU 52 determines that there is a request to divide the intake asynchronous injection (S44). On the other hand, when the CPU 52 determines that the logical sum is false (S48: NO), the CPU 52 sets one intake asynchronous injection (S50).

When the processing of S44 and S50 is completed, the CPU 52 ends the series of processing shown in FIG. 5 once.
Here, the operation and effect of the present embodiment will be described.

  When the rotation speed NE is lower than the prescribed speed NEL, the CPU 52 divides the intake asynchronous injection into two. When the rotational speed NE is higher than or equal to the prescribed speed NEL but lower than the predetermined speed NEH, the CPU 52 determines whether the intake phase difference DIN, the exhaust phase difference DEX, or the change rate of the EGR target value θ * is large. Is divided into two times. Then, after the first intake asynchronous injection, before the second intake asynchronous injection, the required injection amount Qd is updated based on the latest valve-closing inflow air amount Mc. Since the valve-closing inflow air amount Mc referred to here is predicted at a timing close to the actual combustion stroke, it was used for calculating the required injection amount Qd prior to the first intake asynchronous injection. There is a tendency that the value is closer to the actual air amount than the inflow air amount Mc when the valve is closed. For this reason, even when the speed of change of the intake phase difference DIN, the exhaust phase difference DEX, and the EGR target value θ * is large, a decrease in controllability of the air-fuel ratio can be suppressed.

  In addition, if there is a request for the multi-injection processing without using the processing in FIG. 5, it is conceivable that the intake asynchronous asynchronous injection is always divided into two and executed, but in this case, the number of times the port injection valve 16 is driven Therefore, there is a concern that the durability of the port injection valve 16 may be reduced.

<Correspondence>
The correspondence between the items in the above embodiment and the items described in the “Means for Solving the Problems” section is as follows. In the following, the correspondence is shown for each number of the solving means described in the column of "means for solving the problem". [1] The actuators correspond to the throttle valve 14, the intake side valve timing adjustment device 44, the exhaust side valve timing adjustment device 46, and the EGR valve 37, and the reference actuator is the intake side valve timing adjustment device 44, the exhaust side valve timing. It corresponds to the adjusting device 46 and the EGR valve 37. The required injection amount calculation processing corresponds to the processing of S10, and the multi-injection processing corresponds to the processing of S16 to S20 and S24 to S36. The selection processing corresponds to the processing in FIG. The update process corresponds to the process of S22. [2] The valve characteristic variable device corresponds to the intake side valve timing adjustment device 44 and the exhaust side valve timing adjustment device 46. [3] This corresponds to the condition (f) of the processing in S48. Since the opening of the EGR valve 37 is controlled to the EGR target value θ *, the EGR target value θ * can be regarded as the opening of the EGR valve. [4] The prediction process corresponds to the low-pass filter M36, the throttle model M38, the intake manifold model M40, the intake valve model M42, the steady-state value correction process M44, and the intake valve model M48. [5] Corresponds to the processing of S42 to S48.

<Other embodiments>
This embodiment can be implemented with the following modifications. The present embodiment and the following modifications can be implemented in combination with each other within a technically consistent range.

・ "Selection process"
In the process illustrated in FIG. 5, the process of S40 may be deleted. Further, for example, in the process of S48, the above condition (f) may be deleted. The condition (f) is deleted by, for example, setting the EGR target value θ * to be always zero when performing the multi-injection processing, as described in the section “About the operation of the EGR valve” below. This is the most appropriate value, but is not limited to this.

  Further, for example, in the process of S48, the above condition (e) may be deleted. It should be noted that the above condition (e) is deleted when the valve characteristic variable device that changes the valve characteristic of the exhaust valve 30 is not provided, as described in the section “Variable valve characteristic device” below. However, it is not limited to this.

  Further, for example, in the process of S48, the above condition (d) may be deleted. It should be noted that the above condition (D) is most appropriate when there is no variable valve characteristic device for changing the valve characteristic of the intake valve 18 as described in the section “Variable valve characteristic device” below. However, it is not limited to this.

  If the prediction process is not used, for example, as described in the “required injection amount calculation process” section below, in the process of S48, a condition that the rate of change of the opening degree TA of the throttle valve 14 is equal to or higher than a predetermined speed. May be added. In this case, the prescribed speed NEL is set separately from the prediction processing. Of course, the processing of S42 and S46 may be deleted. Further, for example, when the affirmative determination is made in the process of S42 in FIG. 5, when the change speed of the opening degree TA is equal to or higher than the predetermined speed, it is determined that there is a request to split the intake asynchronous injection, and when the speed is lower than the predetermined speed. , The process may proceed to S46.

・ "EGR valve operation"
In the above embodiment, the EGR target value θ * is set based on the rotation speed NE and the charging efficiency η, but the present invention is not limited to this. For example, when a request for the multi-injection process occurs, the EGR target value θ * may be always set to zero.

・ About the required injection amount
The required injection amount Qd may be such that the base injection amount is corrected by the learning value LAF in addition to the low temperature increase coefficient Kw and the feedback correction coefficient KAF. Incidentally, the process of calculating the learning value LAF is a process of inputting the feedback correction coefficient KAF and updating the learning value LAF such that the correction ratio of the base injection amount by the feedback correction coefficient KAF becomes small. Note that the learning value LAF is desirably stored in an electrically rewritable nonvolatile memory.

  Further, the required injection amount Qd may be calculated by, for example, feedforward control based on the disturbance fuel ratio such that the required injection amount Qd is smaller when the disturbance fuel ratio is large than when it is small. Here, the disturbance fuel ratio refers to the amount of fuel (disturbance fuel) flowing into the combustion chamber 24 of the internal combustion engine 10 in addition to the fuel injected from the port injection valve 16 in one combustion cycle. It is the ratio to the total amount of fuel. As the disturbance fuel, for example, a canister that collects fuel vapor from a fuel tank that stores fuel injected from the port injection valve 16, and an adjustment device that adjusts the amount of fluid in the canister flowing into the intake passage 12. Is provided in the internal combustion engine, there is fuel vapor flowing into the intake passage 12 from the canister. Further, for example, when a system for returning fuel vapor in the crankcase to the intake passage 12 is provided, there is fuel vapor flowing into the intake passage 12 from the crankcase.

・ "About asynchronous intake injection"
In the above-described embodiment, the intake asynchronous injection is performed such that the fuel injected from the port injection valve 16 reaches the position before the intake valve 18 opens before the intake valve 18 closes. But it is not limited to this. For example, when the rotational speed NE is high and the required injection amount Qd is excessively large, a part of the period in which the fuel injected from the port injection valve 16 reaches the position before the intake valve 18 is opened is partially opened. It may overlap with the valve period.

・ "Single injection processing"
In the above embodiment, the single injection process is performed such that the fuel injected from the port injection valve 16 reaches the position before the intake valve 18 opens before the intake valve 18 closes. But it is not limited to this. For example, when the rotation speed NE is high and the required injection amount Qd is large, a part of the period in which the fuel injected from the port injection valve 16 reaches the position before the intake valve 18 is opened is part of the intake valve 18. It may overlap with the valve opening period. Note that it is not essential to execute the single injection processing.

・ "About the method of dividing the required injection amount"
In the above embodiment, the synchronous injection amount Qs is variably set based on the rotation speed NE, the charging efficiency η, the water temperature THW, and the intake phase difference DIN, but the invention is not limited to this. For example, a base injection amount may be used instead of the charging efficiency η as a load parameter that is a parameter indicating the amount of air charged into the combustion chamber 24. In addition, four parameters of the load parameter, the rotation speed NE, the water temperature THW, and the intake phase difference DIN are variably set based on only three of them, or variably set based on only two of them. It may be variably set based on only one parameter. At this time, it is desirable that at least one of the load parameter and the water temperature THW be variably set using as much as possible. In addition to the above four parameters, for example, an intake pressure or a flow rate of intake air may be used. However, according to the above four parameters, it is possible to grasp the intake pressure and the flow velocity of the intake air.

  Further, it is not essential to calculate the synchronous injection amount Qs itself. For example, a synchronous injection ratio Ks which is a ratio of the synchronous injection amount Qs to the base injection amount may be determined according to a load or the like. Further, for example, a value obtained by dividing the value “KAF · Qb” obtained by correcting the base injection amount Qb by the feedback correction coefficient KAF by the synchronous injection ratio Ks may be used as the synchronous injection amount Qs. In this case, the synchronous injection amount Qs is “Ks · KAF · Qb”.

・ “Valve characteristic control processing”
In the above embodiment, the target intake phase difference DIN * is variably set in accordance with the operating point of the internal combustion engine 10, but is not limited to this. For example, when the water temperature THW is low, the actual timing may be exceptionally limited to the retard side with respect to the opening timing of the intake valve 18 determined according to the operating point of the internal combustion engine 10.

  In the above embodiment, the overlap amount is variably set based on the operating point of the internal combustion engine 10, and the target exhaust phase difference DEX * is calculated based on the overlap amount and the target intake phase difference DIN *. However, the present invention is not limited to this. . For example, the target exhaust phase difference DEX * may be directly calculated from the operating point of the internal combustion engine 10.

・ "Request injection amount calculation process"
In the above-described embodiment, the required injection amount Qd is calculated based on the valve-closing inflow air amount Mc as the amount of air charged into the combustion chamber 24, but is not limited thereto. For example, the required injection amount Qd may be calculated by grasping the air amount based on the intake air amount Ga and the rotation speed NE without using an air model (prediction process).

・ "Prediction process"
The air model for predicting the valve-closing inflow air amount Mc is not limited to the air model illustrated in FIG. For example, the steady-state value correction process M44 and the intake valve model M48 may not be provided, and the valve-closing inflow air amount Mc1 output from the intake valve model M42 may be used as the input of the injection valve operation process M50.

・ “Variable valve characteristics device”
The variable valve characteristic device that changes the characteristics of the intake valve 18 is not limited to the intake valve timing adjustment device 44. For example, the lift amount of the intake valve 18 may be changed. In this case, the control amount by the variable valve characteristic device that changes the characteristics of the intake valve 18 is the lift amount of the intake valve 18 instead of the intake phase difference DIN.

  The valve characteristic variable device that changes the characteristics of the exhaust valve 30 is not limited to the exhaust valve timing adjusting device 46. For example, the lift amount of the exhaust valve 30 may be changed. In this case, the control amount by the valve characteristic variable device that changes the characteristic of the exhaust valve 30 is the lift amount of the exhaust valve 30 instead of the exhaust phase difference DEX.

  It should be noted that instead of having both a valve characteristic variable device for changing the characteristics of the intake valve 18 and a valve characteristic variable device for changing the characteristics of the exhaust valve 30, only one of them may be provided. Further, it is not essential to provide a variable valve characteristic device.

・ About the control device
The control device is not limited to the one including the CPU 52 and the ROM 54 and executing software processing. For example, a dedicated hardware circuit (for example, an ASIC or the like) that performs hardware processing on at least a part of the software processing in the above embodiment may be provided. That is, the control device may have any of the following configurations (a) to (c). (A) A processing device that executes all of the above processing in accordance with a program, and a program storage device such as a ROM that stores the program. (B) A processing device and a program storage device that execute a part of the above processing according to a program, and a dedicated hardware circuit that executes the remaining processing. (C) A dedicated hardware circuit that executes all of the above processing is provided. Here, there may be a plurality of software processing circuits including a processing device and a program storage device, and a plurality of dedicated hardware circuits. That is, the above processing may be performed by a processing circuit including at least one of one or more software processing circuits and one or more dedicated hardware circuits.

·"others"
It is not essential that the internal combustion engine 10 includes the throttle valve 14.

  Reference Signs List 10 internal combustion engine, 12 intake passage, 14 throttle valve, 16 port injection valve, 18 intake valve, 20 cylinder, 22 piston, 24 combustion chamber, 26 ignition device, 28 crankshaft, 30 ... exhaust valve, 32 ... exhaust passage, 34 ... catalyst, 36 ... EGR passage, 37 ... EGR valve, 38 ... timing chain, 40 ... intake side camshaft, 42 ... exhaust side camshaft, 44 ... intake side valve timing adjustment device 46, an exhaust valve timing adjusting device, 50, a control device, 52, a CPU, 54, a ROM, 56, a power supply circuit, 60, a crank angle sensor, 62, an air flow meter, 64, a throttle sensor, 66, an air-fuel ratio sensor, 70: intake side cam angle sensor, 72: exhaust side cam angle sensor, 74: water temperature sensor, 76: atmospheric pressure sensor, 78: accelerator sensor.

Claims (5)

A control device applied to an internal combustion engine including a port injection valve that injects fuel into an intake passage, and an actuator that adjusts inflow of fluid to a combustion chamber,
A required injection amount calculation process of calculating a required injection amount that is a required fuel amount in one combustion cycle based on a predicted value of the amount of air flowing into the combustion chamber;
A synchronous injection amount that is an injection amount of the intake synchronous injection that injects fuel in synchronization with an opening period of the intake valve, and an injection amount of the intake asynchronous injection that injects the fuel at a timing advanced from the intake synchronous injection. A multi-injection process that divides the required injection amount into an asynchronous injection amount and operates the port injection valve to execute the intake asynchronous injection and the intake synchronous injection in this order.
Prior to the intake synchronous injection, a selection process of selecting whether to execute the intake asynchronous injection divided into two or only once.
In the case where the intake asynchronous injection is divided into two times, the required injection amount is updated and the asynchronous injection amount and the synchronous injection amount are updated before the second intake asynchronous injection is performed. Execute the update process,
When the change speed of the control amount by the reference actuator is equal to or higher than a predetermined speed, the selection process includes a process of selecting to execute the intake asynchronous injection separately in two times,
The control device for an internal combustion engine, wherein the reference actuator refers to a change speed of a control amount in the selection processing among the actuators. The reference actuator includes a valve characteristic variable device that changes at least one of two timings of an intake valve opening start timing and an exhaust valve closing start timing,
In the selection process, when the change speed of the control amount by the valve characteristic variable device is equal to or higher than the predetermined speed as the change speed of the control amount by the reference actuator, it is selected to execute the intake asynchronous injection separately in two times. The control device for an internal combustion engine according to claim 1, further comprising: The internal combustion engine includes an EGR passage that communicates the intake passage with an exhaust passage of the internal combustion engine,
The reference actuator includes an EGR valve that adjusts a cross-sectional area of the passage in the EGR passage,
The selection process is a process of selecting to execute the intake asynchronous injection in two separate steps when the rate of change of the degree of opening of the EGR valve is equal to or higher than the predetermined rate as the rate of change of the control amount by the reference actuator. The control device for an internal combustion engine according to claim 1, comprising: A throttle valve is provided in the intake passage,
Opening degree target value setting processing for setting an opening degree target value of the throttle valve according to an accelerator operation amount;
Delay processing for delaying the aperture target value;
A throttle control process for controlling the opening degree of the throttle valve to the target opening degree subjected to the delay processing;
4. The control device for an internal combustion engine according to claim 2, further comprising: performing a prediction process of calculating the predicted value that is an input of the required injection amount calculation process based on the target opening before the delay process is performed. 5. . The reference actuator does not include the throttle valve,
The selection process includes:
When the rotation speed of the crankshaft of the internal combustion engine is less than a prescribed speed, a process of selecting to execute the intake asynchronous injection in two separate steps;
When the rotation speed is equal to or higher than the specified speed and is lower than a predetermined speed that is higher than the specified speed, and when the changing speed of the control amount by the reference actuator is equal to or higher than the predetermined speed, the intake asynchronous injection is performed twice. Processing to choose to execute separately
5. The control device for an internal combustion engine according to claim 4, further comprising a process of selecting to perform the intake asynchronous injection once when the rotation speed is equal to or higher than the predetermined speed.